The present invention relates to a low-cost automatic implement lock-up system with a shock-absorbing cushioning spring assembly for releasably raising and lowering implements mounted to vehicles which can be operated by a single user.
It is common practice in the farming and construction industries to attach a variety of implements to vehicles. These attachable implements provide low-cost functionality and versatility to existing vehicles. For example, finishing harrows are often attached to the carriage of cultivating machinery.
Several implements may be attached to a single vehicle so that multiple functions can be performed sequentially or simultaneously. In farming applications, a number of variables determine which implement the operator will elect to utilize at a given time, including the operation to be performed, the soil conditions, and the time of year. As a result, the operator needs a method to engage or disengage one or more of the implements, independently. Further, because some implements are mounted close to the ground, they will need to be raised for transport, especially over paved roads.
However, a number of problems exist with present methods for raising implements above the surface of the ground for transport. The prior art discloses methods for manually lifting each of the implements and manually engaging a lock-up mechanism. Because of the weight of many implements, it is often not possible for a single operator to lift the implement and simultaneously activate the lock-up mechanism. Generally, two operators are required, one to raise the implement and another to engage the lock-up mechanism.
In the alternative, a number of automatic systems exist for raising and lowering implements. For example, U.S. Pat. No. 4,534,416 issued to Johnson discloses a hydraulic ram which raises and lowers the entire implement. The hydraulic ram also folds-in lateral extensions or "wings" which contain additional implements. However, automatic raising mechanisms add significant cost and weight to attachable implements. The user must also provide a power source for the raising mechanism, which may not be readily available on the vehicle.
Further, both the manual and automatic lock-up systems of the prior art retain the raised implements in a rigid state. Consequently, during transport over rugged terrain, the implements and their respective mounting structures are subject to potentially damaging shock loads.